gn: Employ the same INSERT_VARIABLE macro trick for switches.cc

gn: Employ the same INSERT_VARIABLE macro trick for switches.cc

This applies the macro trick used in variables.cc to clean up
GetSwitches() function.

BUG=None
R=brettw@chromium.org

Committed: https://crrev.com/d00cdf71c4e5ab4aa73cfa5f251a526e60cc2aba
Cr-Commit-Position: refs/heads/master@{#306691}

[brettw, 2014-12-03 17:57:33]

https://codereview.chromium.org/778513003/diff/1/tools/gn/switches.cc
File tools/gn/switches.cc (right):

https://codereview.chromium.org/778513003/diff/1/tools/gn/switches.cc#newcode169
tools/gn/switches.cc:169: : short_help(NULL),
I'm not sure we want to change this. I want them to default to "no help" and the
callers expect these strings to be non-null.

[tfarina, 2014-12-03 20:56:24]

https://codereview.chromium.org/778513003/diff/1/tools/gn/switches.cc
File tools/gn/switches.cc (right):

https://codereview.chromium.org/778513003/diff/1/tools/gn/switches.cc#newcode169
tools/gn/switches.cc:169: : short_help(NULL),
On 2014/12/03 17:57:33, brettw wrote:
> I'm not sure we want to change this. I want them to default to "no help" and
the
> callers expect these strings to be non-null.

Done.

[brettw, 2014-12-03 21:02:41]

The CQ bit was checked by brettw@chromium.org

[brettw, 2014-12-03 21:02:41]

lgtm

[commit-bot: I haz the power, 2014-12-03 21:03:59]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/778513003/20001

[commit-bot: I haz the power, 2014-12-03 22:29:15]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2014-12-03 22:30:18]

Patchset 2 (id:??) landed as
https://crrev.com/d00cdf71c4e5ab4aa73cfa5f251a526e60cc2aba
Cr-Commit-Position: refs/heads/master@{#306691}